Various ways of recording are known; one of them utilizes an electrode which, when energized, burns off a metalized layer or coating applied to a substrate, for example a ribbon or web or tape of paper, a polyester such as "MYLAR".RTM., or the like. Upon energization of the electrode, in accordance with an electrical pulse generator, the electrode covering the electrosensitive coating will burn off a pattern of dots; the surface of the substrate, which may have a contrasting or colored lacquer or other inking material applied thereto will thus be exposed, and a recording image can be obtained which is representative of the pulse pattern applied to the electrode. The web or strip of substrate is transported beneath the electrodes, preferably at a uniform speed.
Substrates which have been used and which are suitable may also be in the form of individual sheets, rather than of tapes or ribbons. The electrosensitive coating may be made of zinc, aluminum, or a zinc-cadmium compound, and is applied to the substrate, typically by vapor deposition. The pattern which is burned off will correspond to the application of signal pulses to the electrodes, with respect to time, as the web passes thereunder; the electrodes, typically, are formed as comb, of closely adjacent electrode elements which can be individually energized, arranged in a line across the web and transversely to the direction of movement thereof. The electrodes can be energized either by pulses or by a modulated voltage. To increase the contrast, and to improve the resistance to corrosion of the recording material, it has been proposed to apply a layer of ink or lacquer, for example black, beneath the electrosensitive coating. The recorded information can thus be easily read visually, and contrast is improved.
The system is suitable both for reflective reading, that is, for use with an opaque substrate; it is equally possible to use a substrate which is transparent, or to use a substrate which is made of a material which permits reproduction, for example in blueprint apparatus, or the like. For such use, a transparent lacquer is used rather than a contrasting ink layer, and the substrate itself can be suitably inked or colored, and made transparent, for example of a transparent plastic which, further, may be dyed with a suitable color.
The processes and apparatus for reproduction of this type permit good contrasting use in black-white with intermediate grey tones, in which the brightness is controlled by suitable control of the subdivision of a scanning pattern, or of scanning dots, and in which the size of the burn-out dots forming a raster or scanning pattern can be controlled to, for example, control the size of the dots or spots being burned out, so as to obtain more or less, respectively, darkness or brightness content within a grey scale.
The referenced applications by the inventors hereof and the referenced application Ser. No. 222,999, Jung et al., disclose systems and methods also suitable for multi-color recording using an electrosensitive recording process or system.